JPS6290247A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To make it possible to discharge the foreign matter present in an ink emitting port along with an ink liquid, by mounting a cleaning member for cleaning the ink emitting port, a connection member, a connection means, a discharge means and a cleaning control means and emitting the ink liquid from all of emitting ports especially after the emitting surface of each emitting port has been cleaned. CONSTITUTION:A connecting member 312 and a connecting means 330 having a cleaning member 310 connectable to an emitting port 302 and cleaning the same at the time of connection, a discharge means discharging ink stored in the vicinity of the emitting port 302, a cleaning control means 382 driving the connection means 330 before receiving a recording start order signal C to allow the cleaning member 310 to clean the emitting port 302 an emission control means 384 for driving a drive means 304 to perform emission and a control means 386 enabling the reception of the command signal are mounted. By this constitution, the emitting port is held to a clean optimum emitting state before recording. Because the foreign matter capable of being mixed in the vicinity of the emitting port can be removed by emission treatment after the cleaning of the emission port, emission becomes stable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device.

[Traditional branch technique]

Generally, in an inkjet recording apparatus, when not recording, ink liquid is left inside an ink ejection opening such as a nozzle of a recording head.

Conventional inkjet recording devices are equipped with a capping means that can be bonded to the nozzle tip of the recording head, and by performing the bonding when not recording, the recording head is sealed from the surrounding atmosphere with a lid on, so to speak. There is also a method in which the air layer at the joint portion is filled with ink vapor to bring it to a saturated vapor pressure, thereby preventing the ink liquid in the nozzle from drying out and increasing its viscosity.

However, in such devices, in low-humidity environments or when recording is stopped for a long period of time, an increase in the viscosity of the ink cannot be avoided even if gearing is performed as described above to prevent drying. It is difficult to prevent ink from being ejected from the ink.

In order to eliminate such inconveniences, suction is performed through a capping means to create a low pressure state in the air layer and suck out the ink inside the nozzles of the print head, and the ink supply system including the print head is There is an inkjet recording apparatus in which a pump means is provided and is operated automatically or manually to pressurize the ink and discharge the ink from all nozzles of the recording head.

[Problem that the invention seeks to solve]

However, even with such an inkjet recording apparatus, no consideration has been taken to ensure that the apparatus can always be used in the best condition regardless of the surrounding environmental conditions or recording operation conditions.

[Means for solving problems]

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems and provide an inkjet recording apparatus that can always perform recording in an optimal state under any conditions.

Therefore, in the present invention, as shown in FIG.

An ejection port 30 that ejects ink onto the recording surface of the recording material
2 and a driving means 304 for driving the ejection, a cleaning member 31 that can be joined to the ejection port 302 and that cleans the ejection port 302 during the bonding.
0, a joining means 330 that performs joining lra theory to the discharge port 302 of the joining member 312,
A discharge means for discharging the ink accumulated near the discharge port, and a joining means 33 before making it possible to receive the command signal C to start recording.
0 to clean the discharge port 302; a discharge control means 384 which drives the drive means to discharge after cleaning; and a discharge control means 384 which drives the drive means to discharge after the cleaning; The present invention is characterized in that it includes a control means 386.

[Function] That is, according to the present invention, at the start of recording, the ejection port is kept clean and the ejection condition is kept in an optimal state, and the ejection process after cleaning the ejection port prevents contamination near the ejection port. Since it is possible to remove wet foreign substances, the discharge is stable under any conditions, and safety is also improved.

[Example] FIG. 2 is a perspective view showing an outline of the inkjet recording apparatus of the present invention. Here, 12 is a platen roller that is driven by a motor 12A (see FIG. 4), conveys a recording material (not shown) such as paper, and forms and holds a recording surface, and is used for continuous paper or cut paper. The recording material of this type is conveyed between the recording head 15 and the platen roller 12 while being pressed against the platen roller 12 by a pinch roller (not shown). The recording head 15 is mounted on the carriage 14, and has two guide rails 13a and 13b.
The recording medium is driven in the direction S in the figure along the arrow , and recording is performed on the recording material in the process. The carriage 14 is connected to a shaft 17 of a motor 16 via a belt 19 provided between pulleys 18a and 18b and a pulley 18a, and is driven in the S direction in accordance with the rotation of the motor 16.

The recording head 15 has one color, for example, yellow (Y), magenta (
It has four recording units corresponding to four colors: M), cyan (C), and black (B). Those Y, M, C
and the recording unit that records B, respectively.
Gear pumps 23Y, 23M, 23G and 23 are installed on the way.
Supply pipes (pipes) 21Y, 21M,
Ink tank 22Y via 21G and 21B
, 22%, 22G and 22B. Furthermore, these units are also connected to corresponding ink tanks via pipes that do not have gear pumps in the middle. In addition, in FIG. 2, this pipe is designated as pipe 2 for supplying yellow ink for the sake of simplicity.
Only 4Y is illustrated.

100 is the home position 1 of the recording head 15 (at P, it faces the ejection part of the head 15 and moves in the f direction to the head 1).
This is a joint that can be joined to 5.

FIG. 3 shows each recording unit 7 constituting the recording head 15.
31 in Fig. 0 shows an example of the structure of aluminum or Si.
The substrate is made of a material such as C, and a base layer 32 made of Si is laminated thereon. This base layer 32 is cut out from the S1 wafer, and the nozzle portion will be formed on this base layer 32.

On the base e32, there is an electrothermal transducer (heater) driven by the image signal supplied from the control unit (see Figure 4).
Heat storage layer 33 for retaining heat generated from 38 for a predetermined time
However, for example, S10. It is formed by. This heat storage layer 3
A heater 38 made of, for example, HfB2 is disposed in the ink flow path 38 formed on the surface of No. 3, and is connected to a control section via an electrode made of aluminum or the like (not shown). This heater 38 is heated approximately 5 to 5 times per 1 pulse of the image signal.
Electricity is applied for 15 seconds, thereby carefully heating and vaporizing the ink liquid in the ink flow path 39, which causes the ejection port 3
Ink droplets are ejected from step 7. Although the surface of the heater 38 is not shown, it is made of 5i02, Ta, which has excellent electrical insulation, heat resistance, liquid resistance, and cavitation resistance.
covered with materials such as

The partition wall 36 that limits the ink flow path 39 and the ceiling plate 35 can be formed by exposing a dry film, and are bonded together via an adhesive layer 34. Also, the ink flow path 3
Ink is supplied to the liquid chamber 8 through a liquid chamber 40, to which the pipe mentioned above is connected.

The recording unit 7 configured as described above is mounted on the carriage 14 via a mounting member (not shown) provided on the substrate 31, with the ejection ports 37 aligned in the vertical direction in FIG. Four pieces are mounted and fixed to form the recording head 15.

FIG. 4 shows an example of the configuration of the control system of the inkjet recording apparatus of the present invention. In FIG. 4, 22 is a tank 22 storing ink liquid.
These tanks are representative of Y, 22M, 22G, and 22B. An ink cartridge 3 is provided above the ink tank 22, and the ink in the ink cartridge 3 is replenished by a so-called chicken feed method so that the amount of ink in the ink tank 22 is always constant. It is desirable for the liquid level of the ink in the ink tank 22 to be kept constant in order to eject the ink stably. By placing the ink in the recording unit 7 at a position lower than the height of the recording unit 7 and applying a slight negative pressure to the ink inside the recording unit 7, ink does not leak from the ejection ports 37 during non-ejection.

Reference numeral 23 indicates pumps 23Y, . . . , 23 in FIG.
21 represents the pipes 21Y, . . . , 21B, and 24 represents the pipe 24Y. Here, the pump 23 is disposed below the ink tank 22 to prevent air from entering the pipe 21 easily. The pump 23 operates when it is predicted that the viscosity of the ink in the recording unit 7 will become high and normal ejection will not be possible, and pumps the ink to the recording unit 7. It is used to discharge the ink inside from the ejection port 37, and the pump 23 is kept stopped during recording. pipe 2
4 draws out a part of the ink liquid in the recording unit 7 when the pump 23 is operated to discharge air bubbles taken into the recording unit 7, and also connects one pipe 2 during recording.
This is provided in order to smoothly supply ink, which tends to be insufficient in the case of No. 1.

That is, in this embodiment, since ink is supplied to the recording unit 7 by capillary action when the ink is discharged from the discharge port 37, ink is supplied to the recording unit 7 through a relatively thin pipe. When performing image recording with a large number of ejections, it is conceivable that ink replenishment cannot keep up.

In particular, if a pump 23 such as an air pump is provided in the middle of the pipe 21 as in this embodiment, this gear pump will obstruct the flow of ink, so it is preferable to provide one additional supply pipe with less resistance. . However, it goes without saying that the pipe may be made of a single piece of wood as long as the ink can be refilled smoothly even with a single piece of wood.

In this embodiment, air bubbles mixed into the recording unit 7 are transferred from the liquid chamber of the recording unit to the pipe 24 side by the pressure of the ink supplied to the recording unit 7 via the pipe 21 by the gear pump 23. However, in this case, the pipe 24 must be set so that ink is pushed out from the discharge port 37 of the recording unit 7 and air bubbles are transferred to the pipe 24 side, and the recording unit 7 is not destroyed by the ink pressure. Therefore, in this embodiment, a pipe having a diameter smaller than that of the pipe 21 is selected as the pipe 24, and is connected above the unit 7 from the pipe 21.

8.8 and 45 are respectively provided on the side surfaces of the recording unit 7, and are a heater having a nichrome wire or the like as an external heating means for heating the ink from the outside of the recording unit 7, and a heater having a nichrome wire or the like as an external heating means for heating the ink from the outside of the recording unit 7; A thermistor serves as a detection means for the detection, and a temperature control unit that energizes the heater 8 in accordance with the detection output of the thermistor 9 to maintain the ink liquid temperature at an appropriate value.

The temperature control unit 45 can be configured with, for example, a simple logic circuit, a driver, etc., and for example, when it is detected by the detection signal of the thermistor 9 that the ink liquid temperature is 15°C or less,
The heater 8 is energized and the ink liquid temperature in the recording unit 7 is set to 1.
Control is performed to raise the temperature to 5°C. Alternatively, the higher the temperature of the ink liquid, the lower the viscosity and the better the high-speed response. Therefore, when the recording speed is particularly high, it is preferable to set the recording unit 7 at a temperature within the range of 25°C to 55°C. 3
Since it is preferable to use the recording unit in the range of 0°C to 50°C, in this case, the heater 8 is energized at the same time as the power is turned on, and control is performed to raise the recording unit 7 to the above-mentioned predetermined temperature range. It's okay.

Note that a positive characteristic thermistor with an appropriately selected operating range may be used as the heating means, and control may be performed in an open loop without using the thermistor 9.

Reference numeral 100 denotes a joint portion having a cap portion lO and a cleaning portion 11 that rotates according to the rotation of the motor 102 and can be joined to the ejection surface 7A having the ejection port 37 of the recording unit 7 at a predetermined rotational position. be.

The cap 10 is a member that is bonded to and covers the ejection surface 7A during non-recording or ejection recovery processing, and a member that collects ink ejected from the ejection ports 37 may also be provided. Further, the cleaning section 11 can be made of a member made of a polymeric culture-absorbing porous material, for example, in the shape of a roller, belt, or chip.

Reference numeral 110 denotes a conveyance unit for joining/separating the joining part 100 from the discharge surface 7A when the carriage 14 is positioned at the home position HP, and includes, for example, a driving means such as a motor and a transmission member such as a gear or a cam. It can be configured by means.

Reference numeral 50 denotes a console provided with operating members for the operator to operate, such as a power switch and a recording start command switch, and a display member for notifying the operator of the device status and the like. 2
00 is a control unit that controls each of the above-mentioned units according to command signals from the console 50, temperature detection signals from the thermistor 8, etc., and includes, for example, a CPU in the form of a microcomputer,
It has a ROM storing the control procedure shown in FIG. 5 to be executed by the CPU, a working RAM, an interface circuit, an amplifier circuit, and the like.

FIG. 5 and FIG. 6 are a flowchart showing an example of a recording processing procedure using an uninvented loading amount, and a timing chart showing an example of a jumping operation sequence, respectively.

When the power is turned on, first, initialization and initial settings of each part are performed in step S1. At this time, if the discharge surface 7A and the cap portion 10 have not been joined, the initial setting is such that the joint is made. Next, in step S3, a determination is made using the detection output of the thermistor 9, and the process waits until the ink liquid reaches a predetermined temperature range. When the ink liquid temperature reaches a value suitable for ejection through the cooperation of the thermistor 9, heater 8, and temperature control unit 45 (time TB in FIG. 6), an affirmative determination is made in step S3, and the process proceeds to step S5. move on. Note that from this point on, the temperature control section 45 controls the heater 8 as appropriate according to the detection output of the thermistor 9.
The temperature of the recording unit 7 is controlled while turning on and off.

In step S5, the pump 23 is operated for a predetermined period of time, for example, several seconds, and the ink flow path 39 of the recording unit 7 is
The ink inside is discharged outward from the discharge port 37. Note that the pressure applied to the ink inside the recording unit 7 at this time is smaller than the force that would destroy the recording unit 7, and larger than the minimum pressure to push out the ink with increased viscosity from the ejection port 37. Do it like this.

When ink is pushed out from the recording unit 7 in this way,
The ejection surface 7A of the recording unit 7 is wetted with ink, and even if ink is ejected as is in subsequent processing, ink droplets may not reach the surface sufficiently. Therefore, in this example, in step S7, the conveying section +10 and the motor 102 are appropriately driven to replace the cap section IO and the cleaning section 11 on the discharge surface 7A.
to absorb the ink liquid adhering to the recording surface 7A (period TC in FIG. 6).

When the cleaning operation of the ejection surface 7A is completed, a signal indicating that recording operation is possible (ready state) is issued, and a display to that effect is displayed on the display section provided on the console 50. At the same time, or slightly before or after this, in step S8, the recording unit 7 is covered again with the cap part 10, the ejection ports 37 are covered and sealed, and several to dozens of ink drops are ejected from all the ejection ports. (time TX in Figure 6). This is because cleaning the ink liquid adhering to the ejection surface 7A with a cleaning member conversely removes foreign matter such as fine dust, paper powder, solidified ink, etc. in the air adhering to the ejection surface 7A from the ejection port 37. This is because there is a high risk of it being pushed inside. Therefore,
A discharge process is performed to discharge foreign matter that has entered the discharge port to the outside. Note that this ejection is equivalent to ejection based on an image signal rather than pressure applied by a pressurizing means, so that the ejection surface does not get wet with the ink liquid.

In the ready state, the determination process in step Sll is performed to wait for input of a recording start command such as a print signal or a copy signal supplied from the console 50 or the host device. When a recording start command is input (time TO in FIG. 6), the cap section 10 detaches from the recording head 15 and performs the subsequent recording process. All the recording units 7 constituting the spatula 15 are driven to eject several to several tens of drops of ink from all the ejection ports 37, respectively. In this case, warm control has already been performed, and the ink unsuitable for recording has been discharged and cleaned, and the operation is the same as normal ink ejection. Therefore, the ejection surface 7A does not get wet, so the cleaning process is performed in this example. Do not do this.

Immediately after this ejection process, the recording head 15
(time TE in FIG. 6), scans the recording paper, and performs recording processing on the image signal supplied from the host device via the control unit 200 in step S15 (at time TF to TG in FIG. 8). period).

Next, in step S17, it is determined whether or not a predetermined amount of recording for one unit, for example, recording processing for one sheet of recording paper, has been performed. Here, if the determination is negative, the process returns to step S15 to continue recording, and if the determination is positive, the process proceeds to step S19, where it is determined whether or not all recording of the supplied image signal has been completed. If an affirmative determination is made in step S19, the process proceeds to step S23, where the ejection surface 7A is capped, and then the process returns to step Sll and waits for the 1-1 next recording start command. Note that when the power is turned off at the end of recording (time TJ in FIG. 6), the recording head 15 remains capped.

If a negative determination is made in step S19, that is, if continuous recording is to be continued, the process advances to step S21,
The head 15 is returned to the home position and joined to the cap portion 10 (time TH in FIG. 6), and ejection is performed from all the discharge ports 37 for a while (time TI in FIG. 6).
The process returns to step S15.

Although this ejection process does not have to be performed under favorable conditions, it is particularly effective when recording an image on a large area recording paper such as Al size or A2 size under a low humidity environment. That is, for example, 128 outlets, 400 DPI
(dots/inch) recording unit with driving frequency IKH
When driven at
In some cases, some of the ejection ports do not eject ink at all, or eject relatively little ink. In such a case,
In a low-humidity environment, the ink in the ink wave path communicating with the ejection port dries and its viscosity increases. Therefore, by performing capping and ink ejection through the process of step S21 after image recording as in this example, subsequent ejection failures can be prevented.
As a result, so-called white spots in the image can be reliably prevented.

In this embodiment, the ejection process is performed after a predetermined amount of recording, that is, after recording one sheet of recording paper. However, when continuous recording is performed under favorable environmental conditions, or when When continuous printing is performed on a relatively small area of recording paper, ejection processing may be performed after the continuous printing is completed. Needless to say, it can be done.

Further, the return destination after the ejection process in step S21 may be set to return to step Sll if, for example, cut paper is used and printing is performed by giving a recording start command for each paper set. Of course.

In addition, in the embodiment, a cleaning section and a carrier.

Although the connecting portions are integrally provided at the joint portions that are rotatable around the axis, it goes without saying that these can have various configurations. Capping and cleaning can also be performed by appropriately positioning the recording head 15 in relation to the process. or,
The cleaning part and the cap part may be integrally provided on a single joint surface of the joint part.

Further, although the heat treatment of the recording unit is controlled by a temperature control section independent from the control section, it can easily be controlled during the process of heating by the control section. . Regarding the heat treatment,
This is not limited to the above-mentioned embodiment in which heating is performed from the outside, but if a recording unit using an electrothermal transducer is used as in this example, for example, driving pulses within a range in which ink is not ejected may be applied to the electrothermal transducer. Heating may be performed from the inside by supplying it as appropriate, or external and internal heating may be used together.

In addition, as a means for discharging the ink in the ink well passage of the recording unit to the outside, in the above embodiment, a pump disposed on the ink supply side is used, but a suction means such as a pump is installed at the joint. The ink in the flow path may be sucked out by providing it on the side and performing suction through the cap when the cap and the ejection surface are joined.

Furthermore, the present invention is applicable to inkjet recording apparatuses that perform recording by ejecting ink onto a recording surface.
Of course, it can be widely applied regardless of its format or recording method. For example, it can be easily applied not only to an inkjet recording device that performs recording by scanning the recording head as in the embodiment, but also to a so-called full multi-type device in which the recording head is arranged across the entire width of the recording paper. can. Further, in addition to the apparatus using the above-mentioned electrothermal converter as the ejection energy generating means, the present invention may also be an inkjet recording apparatus using, for example, an electric/mechanical energy converter.

〔Effect of the invention〕

As explained above, according to the present invention, ejection is always performed in an optimal state even under any I/X environmental conditions or recording operation conditions, thereby improving the safety and image recording quality of the ink side recording device. It can be increased significantly.

In addition, by ejecting ink liquid from all ejection ports after cleaning the ejection surface, foreign matter inside the ejection ports can be discharged together with the ink liquid, making it possible to reduce clogging of the ejection ports. .

In particular, in the above-described embodiment, the ink ejection process is performed immediately after the ink liquid is pressurized by the pressure means and the ink is ejected outside the ejection port, so the viscosity of the ink liquid is not high and foreign matter is not removed. It is more effective to discharge it to the outside.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an inkjet recording apparatus of the present invention, FIG. 2 is a perspective view showing an example of the mechanical configuration of the apparatus of the present invention, and FIG. FIG. 4 is a perspective view showing an example of the configuration of a unit, FIG. , a flowchart illustrating an example of a recording processing procedure by the apparatus of the present invention, and a timing chart illustrating an example of an operation sequence. 7... Recording unit, 7A... Discharge surface, 8... External heater, 8... Thermistor. DESCRIPTION OF SYMBOLS 10... Cap part, 11... Cleaning part, 12... Platen roller, 14... Carriage, 15... Recording head. 21.24... Supply pipe (pipe). 22... Ink tank, 23... Pump, 37... Discharge port, 38... Electrothermal converter (heater), 39... Ink channel, 40... Liquid chamber, 45... -Temperature control section, 50...console. 100...Joint part, 200...Control part. Ink tank Figure 2 Figure 5 Figure 1

Claims (1)

[Scope of Claims] 1) In an inkjet recording apparatus comprising an ejection port for ejecting ink onto a recording surface of a recording material, and a driving means for driving the ejection, the bonding device is capable of being joined to the ejection port and the joining device is a joining member having a cleaning member that cleans the ejection port at times; a joining means for joining/separating the joining member from the ejection port; a discharging means for discharging ink accumulated in the vicinity of the ejection port; and recording start. cleaning control means for driving the joining means to perform the cleaning of the discharge port before making it possible to receive a command signal; and discharge control means for driving the driving means to perform the discharge after the cleaning. An inkjet recording apparatus comprising: a control means capable of receiving the command signal in connection with the ejection. 2) In the inkjet recording apparatus according to claim 1, the bonding member has a cap member that can be bonded to the ejection port and seals the ejection port from the atmosphere when bonded, and the bonding member has a cap member that seals the ejection port from the atmosphere when the bonding member is bonded to the ejection port. An inkjet recording device characterized in that: is performed at the time of said sealing. 3) In the inkjet recording apparatus according to claim 1 or 2, the bonding member has the cleaning member and the cap member so as to be separately bondable to the ejection port, and the ejection means includes: An inkjet recording apparatus characterized in that the joining means is controlled so that the sealing is performed after the cleaning is completed. 4) An inkjet recording apparatus according to any one of claims 1 to 3, wherein the cleaning member is made of a water-absorbing porous material. 5) In the inkjet recording apparatus according to any one of claims 1 to 4, the cleaning means includes a discharge means for discharging ink accumulated near the ejection port, and after the discharge, An inkjet recording apparatus characterized in that the cleaning is performed. 6) In the inkjet recording apparatus according to any one of claims 1 to 5, the ejection means is a pressurizing means disposed midway through an ink supply path toward the ejection port. An inkjet recording device comprising: 7) The inkjet recording apparatus according to any one of claims 1 to 5, wherein the ejection means has a suction means disposed with respect to the cap member. Recording device.